HTTP Header Spy od Michiel Roos

HTTP Header Spy enables you to inspect request- response headers and cookies right after page load with no extra clicks.

Inspect HTTP headers and response times without opening the page inspector tool. View headers right in the page you are looking at.

★ Auto-hide information panels after specified time
★ Response times
★ Server IP
★ XHR and sub-frame requests
★ Headers also available in the browser action popup
★ Follow the full redirect path
★ Show HSTS requests
★ Colorful status indication icons
★ Inspect Form Data, Get parameters and Cookies
★ Micro mode shows just the chosen response headers
★ Position in one of the four corners of the window
★ Easy single-click highlighting of the headers
★ Choose between a light and a dark color-scheme
★ Filter headers to be shown
★ Highlight any string pattern in the header views